Duet 2 Wifi CAN-FD with adaptor

the.hungarian

I'm looking at switching to the stealth-burner tool head for my Voron and it lends itself to using CAN bus but I'd like to keep using my Duet 2 Wifi + DueX5 expansion.

A previous discussion explains why the duet 2 can't do CAN-FD natively but I've found the Seeed studio makes a CAN-FD module which uses the GD32E103 processor. It uses AT commands over a serial link to send CAN messages.

It would connect to a Mellow Fly-SB2040 V2 on the tool head.

It appears to also have SPI connections, its not clear if that can be used for CAN messages or if only the serial interface can be used.

I'm happy to make changes to the firmware to support this, I assume theres a lot of work to create a new type of "tool" but I'm not sure if its feasible to connect it.

Could it be connected to the "temp daughterboard" (SPI) or the Panel Due connector (UART)?
Is there something that would make it a non-starter?

jay_s_uk

@the-hungarian few problems here.
There's pretty much no flash or ram space left on a duet 2 to support CAN-FD so you'd have to cut a lot of features to get the space.
You then wouldn't want to interface with another MCU running some sort of firmware you have no control over, you'd want to something like the MCP2518FD that we use to bring CAN-FD to the STM32F4 boards.
Then finally the mellow SB2040 doesn't officially support RRF as the code that would've supported it is patented by Bosch and we were unable to get a licence.
You'd be much better switching your board to a duet 3 or an STM32H7 board.
Hopefully a mellow SB2040 board that's compatible with RRF will be released very soon (maybe next week if the gods shine upon us)

the.hungarian

@jay_s_uk Ahhh That's the sort of thing I was afraid of. Thanks, I can't justify the expense atm but you've saved me wasting money - I guess I'll save up and do it right

You've gotta love these patents/licences that restrict open standards and in the stop people using their own products - genius.

Exerqtor

@jay_s_uk said in Duet 2 Wifi CAN-FD with adaptor:

@the-hungarian ~~few problems here~~.
~~There's pretty much no flash or ram space left on a duet 2 to support CAN-FD so you'd have to cut a lot of features to get the space.~~
You then wouldn't want to interface with another MCU running some sort of firmware you have no control over, you'd want to something like the MCP2518FD that we use to bring CAN-FD to the STM32F4 boards.
Then finally the mellow SB2040 doesn't officially support RRF as the code that would've supported it is patented by Bosch and we were unable to get a licence.
You'd be much better switching your board to a duet 3 or an STM32H7 board.
Hopefully a mellow SB2040 board that's compatible with RRF will be released very soon (maybe next week if the gods shine upon us)

Don't mean to change subject here, but:

Interesting! How did that forgo the Bosch patent btw? Or won't it have "offical support" for RRF out of the box either?

jay_s_uk

@Exerqtor originally the rp2040 was doing CAN-FD in software and that's what we tried to licence.
We eventually canned that idea and we use an MCP2518FD to do it in hardware instead. The manufacturer of the chip covers the licence.
So the new mellow SB2040 will be supported out the box the same way the RRF36 is

Exerqtor

@jay_s_uk Aha, sweet!